A New View on Impulse Degradation of ZnO-based Ceramics

作者：Yin Guilai^*; Li Jianying; Yao Guang; Li Shengtao

来源：9th International Conference on Properties and Applications of Dielectric Materials, 2009-07-19 to 2009-07-23.

• ZnO-based ceramics
• non-linear coefficient
• impulse degradation

The electrical and dielectric properties of a commercial ZnO-based varistor ceramics were measured in the process of 8/20 mu s impulse current degradation with a current density of 1725A/cm(2). The characteristic of U-I in the pre-breakdown region was mainly investigated. It was found that the varistor voltage U(1mA) Will first increase rapidly with the times of impulse, and then remain stable and finally decrease sharply. Furthermore, a new loss peak emerges in the dielectric spectra after 600 times of impulse degradation, which suggests a new trapping behavior introduced in the degradation process. It was also found that the non-linear coefficient was more sensitive to the degradation process than varistor voltage U(1mA). These phenomena were not reported before.

• 出版日期2009
• 单位电力设备电气绝缘国家重点实验室; 西安交通大学